package netWork;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 86186
 * Date: 2023-10-18
 * Time: 15:48
 */
public class TcpEchoServer {
    ServerSocket serverSocket = null;

    public TcpEchoServer(int port) throws IOException {
        //服务端需要指定端口号
        serverSocket = new ServerSocket(port);
    }
    
    public void start() throws IOException {
        System.out.println("服务端启动");
        ExecutorService service = Executors.newCachedThreadPool();
        while (true) {
            Socket clientSocket = serverSocket.accept();
            service.submit(new Runnable() {
                @Override
                public void run() {
                    try {
                        processConnection(clientSocket);
                    } catch (IOException e) {
                        throw new RuntimeException(e);
                    }
                }
            });
        }
    }

    public void processConnection(Socket clientSocket) throws IOException {
        System.out.printf("[%s %d] 客户端上线\n",clientSocket.getInetAddress(),
                clientSocket.getPort());
        try (InputStream inputStream = clientSocket.getInputStream();
             OutputStream outputStream = clientSocket.getOutputStream()) {
            Scanner scanner = new Scanner(inputStream);
            PrintWriter printWriter = new PrintWriter(outputStream);
            while (true) {
                if (!scanner.hasNext()) {
                    System.out.printf("[%s %d] 客户端下线",clientSocket.getInetAddress(),
                            clientSocket.getPort());
                    break;
                }
                String request = scanner.next();
                String response = process(request);
                printWriter.println(response);
                printWriter.flush();
                System.out.printf("[%s %d] req=%s res=%s\n",clientSocket.getInetAddress(),
                clientSocket.getPort(),request,response);
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        } finally {
            clientSocket.close();
        }
    }

    public String process(String request) {
        return request;
    }

    public static void main(String[] args) throws IOException {
        TcpEchoServer tcpEchoServer = new TcpEchoServer( 9906);
        tcpEchoServer.start();
    }
}
